U.S. patent number 6,649,757 [Application Number 10/345,548] was granted by the patent office on 2003-11-18 for process for producing laurolactam from cyclododecanone.
This patent grant is currently assigned to Ube Industries, Ltd.. Invention is credited to Joji Kawai, Nobuyuki Kuroda, Hideo Shimomura.
United States Patent |
6,649,757 |
Kuroda , et al. |
November 18, 2003 |
Process for producing laurolactam from cyclododecanone
Abstract
Laurolactam having high quality is produced by reacting
cyclododecanone with a hydroxylamine salt of a mineral acid, and
converting the resultant cyclododecanoneoxime to laurolactam
through the Beckmann rearrangement reaction, wherein a content of
each of oxygen atom-containing C.sub.12 organic compounds, for
example, cyclododecenone or epoxycyclododecane, and cycloaliphatic
unsaturated C.sub.12 hydrocarbon compounds, contained, as an
impurity, in the staring cyclododecanone material, is controlled to
1,000 ppm or less.
Inventors: |
Kuroda; Nobuyuki (Ube,
JP), Kawai; Joji (Ube, JP), Shimomura;
Hideo (Ube, JP) |
Assignee: |
Ube Industries, Ltd. (Ube,
JP)
|
Family
ID: |
27532071 |
Appl.
No.: |
10/345,548 |
Filed: |
January 16, 2003 |
Foreign Application Priority Data
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Jan 16, 2002 [JP] |
|
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2002-007549 |
Feb 28, 2002 [JP] |
|
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2002-053903 |
Feb 28, 2002 [JP] |
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2002-053931 |
Mar 29, 2002 [JP] |
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2002-095024 |
Jul 18, 2002 [JP] |
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2002-209935 |
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Current U.S.
Class: |
540/464 |
Current CPC
Class: |
C07D
201/04 (20130101); C07D 201/06 (20130101) |
Current International
Class: |
C07D
201/06 (20060101); C07D 201/04 (20060101); C07D
201/00 (20060101); C07D 225/02 () |
Field of
Search: |
;540/464 |
References Cited
[Referenced By]
U.S. Patent Documents
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5245029 |
September 1993 |
Inaba et al. |
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Foreign Patent Documents
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532 053 |
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Dec 1972 |
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CH |
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0 487 090 |
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May 1992 |
|
EP |
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0 785 188 |
|
Jul 1997 |
|
EP |
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B43 12153 |
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May 1968 |
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JP |
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B48 10475 |
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Apr 1973 |
|
JP |
|
Other References
Ritz, J. et al., "Caprolactam" Ullmann's Encyclopedia of Industrial
Chemistry. Cancer Chemotherapy to Ceramic Colorants, Weinheim, VCH
Verlag, DE, vol. 15, 1986, pp. 31-50, XP002909167..
|
Primary Examiner: Kifle; Bruck
Attorney, Agent or Firm: Piper Rudnick LLP
Claims
What is claimed is:
1. A process for producing laurolactam from cyclododecanone,
comprising reacting cyclododecanone with a hydroxylamine salt of a
mineral acid to prepare cyclododecanoneoxime, and converting the
resultant cyclododecanoneoxime to laurolactam through the Beckmann
rearrangement reaction, wherein a content of each of the oxygen
atom-containing organic compounds having 12 carbon atoms and
cycloaliphatic unsaturated hydrocarbon compounds having 12 carbon
atoms, contained, as an impurity, in the cyclododecanone used as a
starting material, is controlled to 1,000 ppm or less.
2. The process for producing laurolactam as claimed in claim 1,
wherein the total content of the oxygen atom-containing organic
compounds having 12 carbon atoms and the cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms and respectively
contained, as impurities, in the starting cyclododecanone material,
is controlled to 2,000 ppm or less.
3. The process for producing laurolactam as claimed in claim 1 or
2, wherein the oxygen atom-containing organic compounds having 12
carbon atoms and contained, as impurities, in the starting
cyclododecanone material include noncyclo-aliphatic hydrocarbon
compounds and cycloaliphatic hydrocarbon compounds respectively
having at least one carbonyl group per molecule thereof.
4. The process for producing laurolactam as claimed in claim 1 or
2, wherein the oxygen atom-containing organic compounds having 12
carbon atoms and contained, as impurities, in the starting
cyclododecanone material include noncyclo-aliphatic hydrocarbon
compounds and cycloaliphatic hydrocarbon compounds respectively
having at least one epoxy group per molecule thereof.
5. The process for producing laurolactam as claimed in claim 1 or
2, wherein the oxygen atom-containing organic compounds having 12
carbon atoms and contained, as impurities, in the starting
cyclododecanone material include noncyclo-aliphatic hydrocarbon
compounds and cycloaliphatic hydrocarbon compounds respectively
having at least one aldehyde group per molecule thereof.
6. The process for producing laurolactam as claimed in claim 1 or
2, wherein the oxygen atom-containing organic compounds having 12
carbon atoms and contained, as impurities, in the starting
cyclododecanone material include noncyclo-aliphatic hydrocarbon
compounds and cycloaliphatic hydrocarbon compounds respectively
having at least one hydroxyl group per molecule thereof.
7. The process for producing laurolactam as claimed in claim 1,
wherein a content of each of the oxygen atom-containing organic
compounds having 12 carbon atoms and the cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms, and contained, as
impurities, in the starting cyclododecanone material, is controlled
to 500 ppm or less.
8. The process for producing laurolactam as claimed in claim 1,
wherein the starting cyclododecanone material is pre-treated with
an alkali metal hydroxide or toluenesulfonic acid at a temperature
of 70 to 230.degree. C.
9. The process for producing laurolactam as claimed in claim 1,
wherein the starting cyclododecanone material is pre-treated with
at least one member selected from solid acids and ion-exchange
resins at a temperature of 70 to 230.degree. C.
Description
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a process for producing
laurolactam from cyclododecanone. More particularly, the present
invention relates to a process for producing laurolactam having a
high degree of purity from cyclododecanone used as a starting
material.
Laurolactam is useful as a material for producing synthetic resins
such as polyamide resins.
(2) Description of the Related Art
As a conventional method of producing laurolactam, a method in
which cyclodododecanone, having been prepared by oxidizing
cyclododecane with molecular oxygen-containing gas and
dehydrogenating the resultant cyclydodecanol, is reacted, as a
starting material, with a hydroxylamine mineral acid salt to
prepare cyclododecanoneoxime and the resultant cyclododecanoneoxime
is subjected to the Beckmann rearrangement reaction to produce the
target laurolactam, is known. As another method of producing
cyclododecanone, a method in which epoxycyclododecadiene is reduced
with hydrogen and the resultant epoxycyclododecane is isomerized
with an alkali metal salt, etc., to prepare the target
cyclododecanone, is known.
In the method of producing cyclododecanone using, as a starting
material, epoxycyclododecadiene, in the case where the reduction of
epoxycyclododecadiene with hydrogen is incompletely carried out,
the resultant epoxycyclododecane contains an impurity consisting of
epoxycyclododecene and the epoxycyclododecene is converted to
cyclododecenone by the isomerization reaction. The cyclododecenone
is an impurity which is difficult to remove, as an impurity, from
the target cyclododecanone by distillation. Also, in the case where
cyclododecanol is dehydrogenated, cyclododecenone may be produced
as a by-product, when the reaction conditions are
inappropriate.
Further it is known that, in the reaction for isomerizing
epoxycyclododecane in the presence of an alkali metal salt,
undesired compounds having one or more double bonds between carbon
atoms, such as cyclododecadiene, cyclododecene and cyclododecenol
are produced as by-products.
Further, it is known that, in the method in which cyclododecanone,
having been prepared by oxidizing cyclododecane with a molecular
oxygen-containing gas and dehydrogenating the resultant
cyclododecanol, is employed as a starting material for the
production of laurolactam, the cyclododecanone produced by the
oxidation of cyclododecane is further oxidized to produce
1,2-diketone compound and .alpha.-hydroxyketone compound, and the
.alpha.-hydroxyketone compound is further converted to 1,2-diketone
compound (cyclododecane-1,2-dione) during the dehydrogenation
reaction procedure for cyclododecanol.
Where cyclododecanone is produced from a starting material
consisting of epoxycyclododecadiene, the 1,2-diketone compound is
not directly produced. However, when cyclododecanone is handled at
a temperature of 100.degree. C. or more in the presence of a
molecular oxygen-containing gas, the 1,2-diketone compound is
produced. In this case, the 1,2-diketone compound is an impurity
which is difficult to separate from cyclododecanone by
distillation.
Furthermore, it is known that in a method for preparing a mixture
of cyclododecanol with cyclododecanone, by oxidizing cyclododecane
with a molecular oxygen-containing gas, epoxycyclododecane is
produced as a by-product, and in the distillation refining
procedure for isolating refined cyclododecanone from the mixture,
the distilled cyclododecanone fraction contains the above-mentioned
epoxycyclododecane as an impurity.
Still further, it is known that in the case where
epoxycyclododecadiene is used as a starting material for the
production of cyclododecanone, and subjected to an isomerization
reaction thereof, a small amount of cycloundecylcarboxyaldehyde is
produced as a by-product. The cycloundecylcarboxyaldehyde is an
impurity which is difficult to separate from cyclododecanone by
distillation.
Also, in the method of preparing a mixture of cyclododecanol with
cyclododecanone by oxidizing cyclododecane with a molecular
oxygen-containing gas, undecylaldehyde is produced as a by-product
and is contained in refined cyclododecanone fraction obtained by
distillation of the mixture.
When the aldehyde compound-containing cyclododecanone is subjected
to the cyclododecanoneoxime-preparing procedure and then to the
Beckmann rearrangement reaction, the aldehyde compound is converted
to a corresponding amide compound and the amide compound is kept
contained in the target laurolactam. The contained amide compound
causes the quality of the resultant laurolactam to be
decreased.
Furthermore, it is known from the disclosure of Japanese Examined
Patent Publication No. 43-12153 and No. 48-10475 that, in the
production of laurolactam by converting cyclododecanone to an oxime
thereof and subjecting the resultant cyclododecanoneoxime to the
Beckmann rearrangement reaction, if the temperature of the Beckmann
rearrangement reaction is too high, the cyclododecanoneoxime is
decomposed due to the poor thermal stability thereof, and the
resultant laurolactam is unsatisfactory due to the low quality
thereof. However, the prior art does not teach or suggest any
possible influence of oxygen atom-containing organic compounds
having 12 carbon atoms and cycloaliphatic unsaturated hydrocarbon
compounds having 12 carbon atoms, for example, carbonyl
group-containing C.sub.12 -noncyclo-aliphatic and cycloaliphatic
hydrocarbon compounds, epoxy group-containing C.sub.12
-noncyclo-aliphatic and cycloaliphatic hydrocarbon compounds,
aldehyde group-containing C.sub.12 -noncyclo-aliphatic and
cycloaliphatic hydrocarbon compounds, hydroxyl group-containing
C.sub.12 -noncyclo-aliphatic and cycloaliphatic hydrocarbon
compounds contained in the starting cyclododecanone material, on
the quality of the target laurolactam.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a process for
producing laurolactam having high quality, from cyclododecanone,
with a high efficiency.
The above-mentioned object can be attained by the process of the
present invention for producing laurolactam from cyclododecanone,
which comprises reacting cyclododecanone with a hydroxylamine salt
of a mineral acid to prepare cyclododecanoneoxime, and converting
the resultant cyclododecanoneoxime to laurolactam through the
Beckmann rearrangement reaction, wherein a content of each of
oxygen atom-containing organic compounds having 12 carbon atoms and
cycloaliphatic unsaturated hydrocarbon compounds having 12 carbon
atoms, each contained, as an impurity, in cyclododecanone used as a
starting material, is controlled to 1,000 ppm or less.
In the process of the present invention for producing laurolactam,
the total content of the oxygen atom-containing organic compounds
having 12 carbon atoms and the cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms and respectively
contained, as impurities, in the starting cyclododecanone material,
is preferably controlled to 2,000 ppm or less.
In the process of the present invention for producing laurolactam,
the oxygen atom-containing organic compounds having 12 carbon atoms
and contained, as impurities, in the starting cyclododecanone
material may include noncyclo-hydrocarbon compounds or
cycloaliphatic hydrocarbon compounds respectively having at least
one carbonyl group per molecule thereof.
In the process of the present invention, for producing laurolactam,
the oxygen atom-containing organic compounds having 12 carbon atoms
and contained, as impurities, in the starting cyclododecanone
material may include noncyclo-hydrocarbon compounds or
cycloaliphatic hydrocarbon compounds respectively having at least
one epoxy group per molecule thereof.
In the process of the present invention for producing laurolactam,
the oxygen atom-containing organic compounds having 12 carbon atoms
and contained, as impurities, in the starting cyclododecanone
material may include noncyclo-hydrocarbon compounds or
cycloaliphatic hydrocarbon compounds respectively having at least
one aldehyde group per molecule thereof.
In the process of the present invention for producing laurolactam,
the oxygen atom-containing organic compounds having 12 carbon atoms
and contained, as impurities, in the starting cyclododecanone
material may include noncyclo-hydrocarbon compounds or
cycloaliphatic hydrocarbon compounds respectively having at least
one hydroxyl group per molecule thereof.
In the process of the present invention for producing laurolactam,
the content of each of the oxygen atom-containing organic compounds
having 12 carbon atoms and the cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms, and contained, as
impurities, in the starting cyclododecanone material, is preferably
controlled to 500 ppm or less.
In the process of the present invention for producing laurolactam,
the starting cyclododecanone material is preferably pre-treated
with an aqueous solution of an alkali metal hydroxide or
toluenesulfonic acid at a temperature of 70 to 230.degree. C.
In the process of the present invention for producing laurolactam,
the starting cyclododecanone material is preferably pre-treated
with a solid acid at a temperature of 70 to 230.degree. C.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The inventors of the present invention conducted extensive
researches concerning causes of degradation in quantity of the
target laurolactam when produced from a starting cyclododecanone
material, and found that when the starting cyclododecanone material
contained at least one member selected from oxygen atom-containing
organic compounds, usually oxygen atom-containing cycloaliphatic
compounds, having 12 carbon atoms and cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms, as an impurity, in an
amount more than a limited amount, the resultant laurolactam could
not exhibit, even after a distillation refining is applied thereto,
satisfactory quality, for example, a satisfactory differential
light transmittance (which will be referred to as LT.diff,
hereinafter) of 25% or less, preferably 15% or less. Also, the
inventors of the present invention further found that the target
laurolactam having satisfactory quality, for example, a LT.diff of
25% or less, preferably 15% or less could be obtained by
controlling the content of each of oxygen atom-containing organic
compounds having 12 carbon atoms and cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms, contained as
impurities, in the starting cyclododecanone material to a specific
value or less. The process of the present invention was completed
on the basis of the above-mentioned findings.
In the process of the present invention, a starting cyclododecanone
material is subjected to a reaction with a hydroxylamine salt of a
mineral acid to prepare cyclododecanoneoxime, and then the
resultant cyclododecanoneoxime is converted to laurolactam by the
Beckmann rearrangement reaction.
The starting cyclododecanone material usable for the process of the
present invention can be prepared by oxidizing cyclododecane with a
molecular oxygen-containing gas or by isomerizing
epoxycyclododecane. In the oxidation method, cyclododecane is
oxidized with oxygen gas or a molecular oxygen-containing gas in
the presence of a boron compound to provide a reaction product
mixture comprising cyclododecanol and cyclododecanone, the reaction
product mixture is hydrolysed, the boron compound is removed from
the hydrolysis product mixture, non-reacted cyclododecane is
separated and recovered from the hydrolysis product mixture by
distillation, and a mixture of cyclododecanol with cyclododecanone
is collected from the residual fraction. The mixture is subjected
to a dehydrogenation procedure to convert cyclododecanol to
cyclododecanone. In this dehydrogenation procedure, a portion of
the resultant cyclododecanone is occasionally further
dehydrogenated to produce cyclododecenone.
Also, in the oxidation of the starting cyclododecane material with
a molecular oxygen-containing gas, cyclododecane is oxidized into
cyclododecanone and occasionally the resultant cyclododecanone is
further oxidized into C.sub.12 1,2-diketone compounds and C.sub.12
.alpha.-hydroxyketone compounds and, further occasionally, the
resultant C.sub.12 .alpha.-hydroxyketone compounds are
dehydrogenated to produce C.sub.12 1,2-diketone compounds
(cyclododecane-1,2-dione) in the dehydrogenation procedure for
cyclododecanole.
In the process for producing cyclododecanone from
epoxycyclododecadiene by reducing epoxycyclododecadiene with
hydrogen in the presence of a platinum group metal catalyst, and
isomerizing the resultant epoxycyclododecane in the presence of an
alkali metal salt, to produce the target cyclododecanone, if the
reduction reaction of epoxycyclododecadiene with hydrogen is
incompletely conducted, epoxycyclododecene having a
non-hydrogenated double bond remains in the reaction product
mixture. When the epoxycyclododecane material containing
epoxycyclododecene is subjected to the isomerization reaction, the
resultant cyclododecanone contains cyclododecenone.
The cyclododecenone contained, as an impurity in the target
cyclododecanone, is very difficult to separate and remove from the
target cyclododecanone by distillation or other refining
procedures. Thus, the removal of cyclododecenone causes the cost of
production of the target cyclododcanone to increase. Therefore, in
the production of cyclododecanone, the conditions of the production
must be carefully controlled so that the production of
cyclododecenone is prevented.
Also, in the isomerization of epoxycyclododecane in the presence of
an alkali metal salt for the production of the target
cyclododecanone, occasionally, small amounts of cyclododecene,
cyclododecadiene and cyclododecenol are produced as by-products.
These by-product compounds can be separated and removed from
cyclododecanone by distillation. However, the yield of the target
cyclododecanone decreases with increase in degree of refining.
Thus, an increase in refining degree causes an economical
disadvantage in the production of the target compound. The refining
degree of the target compound must be controlled in consideration
of the desired quality of the target cyclododecanone and the
production cost thereof.
In the process for producing cyclododecanone by reducing
epoxycyclododecadiene with hydrogen in the presence of a platinum
group metal catalyst and isomerizing the resultant
epoxycyclododecane in the presence of an alkali metal salt, the
by-product, C.sub.12 1,2-diketone compounds are not directly
produced. However, in the case where cyclododecanone is handled in
the presence of a molecular oxygen-containing gas at a temperature
of 100.degree. C. or more, C.sub.12 1,2-diketone compounds
(cyclododecane-1,2-dione) are produced. As mentioned above, the
production of the diketone compound must be carefully prevented by,
for example, controlling the reaction conditions and/or the
handling conditions.
Further, if the isomerization reaction of epoxycyclododecane is
incompletely carried out, the non-isomerized epoxycyclododecane
remains in the resultant reaction product.
As mentioned above, as the removal of the residual
epoxycyclododecane from the target compound causes the resultant
refined target compound to be costly, the reaction conditions for
the production of the target cyclododecanone must be carefully
controlled.
Further, in the isomerization of epoxycyclododecane, occasionally
cycloundecanecarboxyaldehyde is produced as a by-product. The
by-product cycloundecanecarboxyaldehyde is difficult to separate
and remove from the target cyclododecanone by distillation,
etc.
Accordingly, in the process of the present invention for producing
laurolactam from a starting cyclododecanone material, it is
essential that a content of each of oxygen atom-containing organic
compounds, preferably oxygen atom-containing cycloaliphatic
compounds, having 12 carbon atoms, and cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms, each contained, as an
impurity, in the starting cyclododecanone material is controlled to
1,000 ppm or less, preferably 500 ppm or less, more preferably 300
ppm or less.
When the content of each impurity as mentioned above is controlled
to 1,000 ppm or less, the resultant target laurolactam exhibits
satisfactory quality, for example, a very low LT.diff.
The oxygen atom-containing C.sub.12 organic compounds to be
controlled in the process of the present invention include,
C.sub.12 non-cyclic aliphatic hydrocarbon compounds and C.sub.12
cycloaliphatic hydrocarbon compounds, each containing at least one
carbonyl group per molecule thereof, for example,
cyclododecadienone, cyclododecenone, 1-hydroxycyclododecane-2-one,
and cyclododecane-1,2-dione.
Also, the oxygen atom-containing C.sub.12 organic compounds include
non-cyclic aliphatic C.sub.12 hydrocarbon compounds and
cycloaliphatic C.sub.12 hydrocarbon compounds each having at least
one epoxy group per molecule thereof, for example,
epoxycyclododecane, epoxycyclododecene, epoxycyclododecadiene,
diepoxycyclododecane and diepoxycyclododecene.
Further, the oxygen atom-containing C.sub.12 organic compounds
include C.sub.12 non-cyclic aliphatic hydrocarbon compounds and
C.sub.12 cycloaliphatic hydrocarbon compounds each having at least
one aldehyde group per molecule thereof, for example,
undecylaldehyde and cycloundecanecarboxyaldehyde.
Furthermore, the oxygen atom-containing C.sub.12 organic compounds
include non-cyclic aliphatic C.sub.12 hydrocarbon compounds and
cycloaliphatic C.sub.12 hydrocarbon compounds each containing at
least one hydroxyl group, for example n-dodecanol, cylododecanol,
cyclododecenol, and 1-hydroxycyclododecane-2-one.
The C.sub.12 cycloaliphatic unsaturated hydrocarbon compounds to be
controlled in the process of the present invention are constituted
from only carbon atoms and hydrogen atoms and include, for example,
cyclododecene and cyclododecadiene.
When the starting cyclododecanone material contains two or more
types of the above-mentioned impurities, the total content of the
impurities is preferably controlled to 2,000 ppm or less, more
preferably 1,800 ppm or less, still more preferably 1,500 ppm or
less, furthermore preferably 1,000 ppm or less. If the total
content of the impurities is more than 2,000 ppm, even when each of
the contents of impurities is 1,000 ppm or less, the resultant
laurolactam may exhibit an unsatisfactory quality.
The contents of the impurities, namely, the oxygen atom-containing
C.sub.12 organic compounds and the C.sub.12 cycloaliphatic
unsaturated hydrocarbon compounds, contained in the starting
cyclododecanone material are controlled to the desired level by,
for example, the following means.
To control the contents of the non-cyclic aliphatic or
cycloaliphatic C.sub.12 hydrocarbon compounds having at least one
carbonyl group per molecule thereof, contained, as impurities in
the starting cyclododecanone material each to 1,000 ppm or less,
the reaction conditions for the isomerization of epoxycyclododecane
are carefully controlled and/or the impurity-containing
cyclododecanone material is brought into contact with an aqueous
solution of an alkaline compound, for example, sodium hydroxide and
heat-treated at a temperature of 70 to 230.degree. C., preferably
100 to 200.degree. C., while stirring the mixture, and then the
resultant treatment product is refined by distillation.
To control the contents of the non-cyclic aliphatic and
cycloaliphatic C.sub.12 hydrocarbon compounds having at least one
epoxy group per molecule thereof to 1,000 ppm or less, the reaction
conditions for production of cyclododecanone is carefully
controlled and/or the cyclododecanone material containing the
impurities is heat-treated with at least one member selected from a
solid acids, for example, .gamma.-alumina and/or silica-alumina,
and ion-exchange resins, at a temperature of 70 to 230.degree. C.,
preferably 80 to 220.degree. C.
To control the contents of the non-cyclic aliphatic and
cycloaliphatic C.sub.12 hydrocarbon compounds having at least one
aldehyde group per molecule thereof to 1,000 ppm or less, the
reaction conditions for the production of cyclododecanone are
carefully controlled and/or the impurity-containing cyclododecanone
material is heat-treated together with an alkaline substance, for
example, sodium hydroxide or an acid substance, for example,
toluenesulfonic acid, at a temperature of 70.degree. C. or more,
preferably 70 to 230.degree. C., more preferably 80.degree. C. to
220.degree. C., and/or the impurity-containing cyclododecanone
material is subjected to a reduction treatment with hydrogen in the
presence of a Ru or Ni catalyst, and then the reduction-treated
material is subjected to a precision distillation.
To control the contents of the non-cyclic aliphatic and
cycloaliphatic C.sub.12 hydrocarbon compounds having at least
hydroxyl group per molecule thereof to 1,000 ppm or less, the
reaction conditions for the production of cyclododecanone are
carefully controlled and/or the impurity-containing cyclododecanone
material is subjected to a precision distillation, and/or the
impurity-containing cyclododecanone material is heat-treated in the
presence of an acid substance, for example, toluenesulfonic acid at
a temperature of 70.degree. C. or more, preferably 70 to
230.degree. C., more preferably 80 to 220.degree. C.
To control the contents of the aliphatic unsaturated C.sub.12
hydrocarbon compounds to 1,000 ppm or less, the reaction conditions
for the production of cyclododecanone are carefully controlled
and/or the impurity-containing cyclododecanone material is
subjected to a precision distillation.
In the case where the cyclododecanone material contains two or more
types of impurities, preferably two or more of the above mentioned
refining procedures are applied. However, sometimes, the contents
of two or more impurities can be reduced by a single refining
procedure.
The impurity content-controlled starting cyclododecanone material
is reacted with a hydroxylamine salt of a mineral acid to provide
cyclododecanoneoxime. The mineral acid is preferably selected from
sulfuric acid and hydrochloric acid. The oxime-producing reaction
is preferably carried out at a temperature of 70 to 110.degree. C.,
more preferably 90 to 100.degree. C. Also, the pH of the reaction
mixture is preferably controlled to 1 to 10, more preferably 4 to
10, by using an aqueous alkaline solution, preferably an aqueous
ammonia solution.
A solution of the resultant cyclododecanoneoxime is subjected to
the Beckmann rearrangement reaction to prepare laurolactam.
Preferably the Beckmann rearrangement reaction is carried out by
heating the aqueous cyclododecanoneoxime solution in the presence
of fuming sulfuric acid at a temperature of 90 to 130.degree. C.,
more preferably 90 to 110.degree. C. Cyclododecanoneoxime is in the
state of a solid at room temperature and has a melting temperature
of 135.degree. C. This compound is very unstable at the melting
temperature or higher. Thus, usually cyclododecanoneoxime in the
state of a solution in a solvent is subjected to the Beckmann
rearrangement reaction at the above-mentioned temperature. The
solvent is preferably selected from cycloaliphatic hydrocarbons,
for example, cyclododecane and isopropylcyclohexane; and
alkanoneoximes, for example, cyclohexanoneoximes. After the
reaction, the resultant reaction mixture is neutralized with an
aqueous ammonia solution, and refined by a conventional refining
procedure, for example, extraction or distillation, to collect
refined laurolactam.
EXAMPLES
The present invention will be further explained in detail by the
following examples.
In the examples and comparative examples, the differential light
transmittance (LT.diff) of laurolactam was determined by the
following measurement.
Measurement of LT.diff
A 2% by mass methyl alcohol solution of a sample of laurolactam to
be tested in an amount of 100 ml was mixed with 10 ml of 0.1N
aqueous potassium permanganate solution at a temperature of
20.degree. C. and, 200 seconds after mixing, the resultant mixed
liquid was placed in a 5 mm cell, and 240 second after mixing, a
light transmittance (%) at a wavelength of 410 mm, of the mixed
solution was measured. The resultant data is referred as to T1. In
this measurement, as a reference liquid, a mixture liquid of 100 ml
of a 2% by mass laurolactam solution in methyl alcohol with 20 ml
of methyl alcohol was employed.
Then, 100 ml of methyl alcohol was mixed with 10 ml of a 0.01N
aqueous potassium permanganate solution and, 200 seconds after
mixing, the resultant mixed solution was placed in a 5 mm cell, and
240 seconds after mixing, the light transmittance (%), T2, of the
mixed liquid at a wavelength of 410 mm was measured. In this
measurement, as a reference liquid, distilled water was
employed.
The LT.diff of the sample was calculated in accordance with the
following equation;
Example 1
In a SUS reactor having a capacity of 140 liters, 77 kg of a 15
mass % aqueous hydroxylamine sulfate solution were placed; a 25
mass % aqueous ammonia solution was mixed thereinto to an extent
such that the pH of the mixture is adjusted to 5.5, while the
temperature of the mixture is maintained at 60.degree. C. or less;
then 10 kg of cyclododecanoneoxime was further mixed with the
pH-adjusted mixture and the temperature of the resultant mixture
was adjusted to 90.degree. C. Into the mixture, 9.5 kg of a
starting cyclododecanone material consisting of cyclododecanone
containing, as an impurity, 150 ppm of cyclododecenone were mixed,
and a 25 mass % aqueous ammonia solution was further mixed
therewith to control the pH and temperature of the resultant
reaction mixture to 5.5 and 95.degree. C., respectively. The
reaction mixture was subjected to a reaction at the above-mentioned
temperature for 4 hours, then left to stand for 0.5 hour to allow
the reaction mixture is separated into an aqueous phase layer and a
non-aqueous (organic) phase layer. The aqueous phase layer was
withdrawn from an outlet located in the bottom of the reactor.
Then, the remaining organic phase fraction comprising
cyclododecanoneoxime was withdrawn from the reactor, and the
withdrawn organic phase fraction was fed in a feed rate of 3.6
kg/hr together with a mixture of 13 parts by mass of fuming
sulfonic acid with 9 parts by mass of concentrated sulfuric acid,
in a feed rate of 4 kg/hr, into a Beckmann rearrangement reaction
vessel having a capacity of 10 liters. The temperature of the
mixture in the reaction vessel was maintained at 90 to 100.degree.
C., and the residence time of the mixture in the reaction vessel
was controlled to one hour. The resultant reaction mixture was
withdrawn from the reaction vessel by overflowing, and fed at a
feed rate of 7.6 kg/hr into a neutralization vessel containing
saturated aqueous ammonium sulfate solution, and a 14 mass %
aqueous ammonia solution was fed into the vessel to control the pH
of the mixture in the vessel to 5.5. From the resultant reaction
mixture, an organic phase fraction was separated and collected; the
collected organic phase fraction was subjected to an extraction
with toluene; and the resultant toluene extract was washed with
water and then distilled under a reduced pressure of 0.2 kPa. As a
distillate, refined laurolactam was collected.
The resultant refined laurolactam exhibited a LT.diff of 5.4%.
Example 2
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, as an impurity, 30 ppm of
cyclododecane-1,2-dione.
The resultant refined laurolactam exhibited an LT.diff of 5.2%.
Example 3
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, as an impurity, 50 ppm of
epoxycyclododecane.
The resultant refined laurolactam exhibited an LT.diff of 5.6%.
Example 4
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, 510 ppm of impurities
comprising 160 ppm of cyclododecadiene, 150 ppm of cyclododecenone
and 200 ppm of cyclododecenol.
The resultant refined laurolactam exhibited an LT.diff of 5.4%.
Example 5
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, as an impurity, 250 ppm of
cycloundecanecarboxyaldehyde.
The resultant refined laurolactam exhibited n LT.diff of 6.2%.
Example 6
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing 1,500 ppm of impurities
comprising 700 ppm of cyclododecenone and 800 ppm of cycloaliphatic
unsaturated hydrocarbon compounds having 12 carbon atoms.
The resultant refined laurolactam exhibited an LT.diff of
17.4%.
Comparative Example 1
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, as an impurity, 1,500 ppm
of epoxycyclododecane.
The resultant refined laurolactam exhibited an LT.diff of
27.2%.
Comparative Example 2
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, as impurities, 900 ppm of
cyclododecenone and 1,500 ppm of cyclocyclic unsaturated
hydrocarbon compounds having 12 carbon atoms.
The resultant refined laurolactam exhibited an LT.diff of
28.2%.
Comparative Example 3
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing, as an impurity, 1,500 ppm
of cycloundecanecarboxyaldehyde.
The resultant refined laurolactam exhibited an LT.diff of
28.8%.
Comparative Example 4
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material
consisted of cyclododecanone containing 2900 ppm of impurities
comprising oxygen atom-containing cycloaliphatic compounds having
12 carbon atoms (including 700 ppm of cyclododecenone, 100 ppm of
epoxycyclododecane, 500 ppm of cyclododecenol, 150 ppm of
cyclododecanol and 1,100 ppm of cycloundecanecarboxyaldehyde) and
350 ppm of cyclododecadiene, as a cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms.
The resultant refined laurolactam exhibited an LT.diff of
29.5%.
Table 1 shows types and contents of the impurities in the starting
cyclododecanone material and the LT.diff of the resultant refined
laurolactam of Examples 1 to 6 and comparative Examples 1 to 4.
TABLE 1 Item The starting cyclododecanone material Differential
Impurities light Content transmittance Example No. Type (ppm) (%)
Example 1 Cyclododecenone 150 5.4 2 Cyclododecane-1,2-dione 30 5.2
3 Epoxycyclododecane 50 5.6 4 Cyclododecadiene 160 Cyclododecenone
150 Cyclododecenol 200 5.4 5 Cycloundecanecarboxyaldehyde 250 6.2 6
Cyclododecenone 700 C.sub.12 -Cycloaliphatic 800 17.4 unsaturated
hydrocarbon compounds Comparative Example 1 Epoxycyclododecane 1500
27.2 2 Cyclododecenone 900 C.sub.12 -Cycloaliphatic 1500 28.2
unsaturated hydrocarbon compounds 3 Cycloundecanecarboxyaldehyde
1500 28.8 4 Cyclododecenone 700 Epoxycyclododecane 100
Cyclododecenol 500 Cyclododecanol 150 Cycloundecanecarboxyaldehyde
1100 Cyclododecadiene 350 29.5
Example 7
A refined laurolactam was prepared by the same procedures as in
Example 1, except that the starting cyclododecanone material was
prepared by pre-treating a unrefined cyclododecanone material
containing 700 ppm of cyclododecenone with an aqueous solution of
10% by mass of sodium hydroxide at 200.degree. C. for 5 hours, and
then subjecting the resultant pretreatment reaction mixture to
refining distillation. In the pretreated cyclododecanone material,
the content of cyclododecenone was 80 ppm.
The resultant refined laurolactam exhibited an LT.diff of 5.3%.
Example 8
A refined laurolactam was prepared by the same procedures as in
Example 3, except that the starting cyclododecanone material was
prepared by pre-treating a unrefined cyclododecanone material
containing 2,800 ppm of epoxycylcododecane with .gamma.-alumina at
200.degree. C. for 2 hours, and subjecting the resultant
pretreatment reaction mixture to refining distillation. In the
pretreated cyclododecanone material, the content of
epoxycylcododecane was 170 ppm.
The resultant refined laurolactam exhibited an LT.diff of 5.8%.
Example 9
A refined laurolactam was prepared by the same procedures as in
Example 5, except that the starting cyclododecanone material was
prepared by pre-treating a unrefined cyclododecanone material
containing 1,500 ppm of cycloundecanecarboxyaldehyde with an
aqueous solution of 10% by mass of sodium hydroxide at 180.degree.
C. for 10 hours, and subjecting the resultant pretreatment reaction
mixture to refining distillation. In the pretreated cyclododecanone
material, the content of cycloundecanecarboxyaldehyde was not
detected.
The resultant refined laurolactam exhibited an LT.diff of 5.0%.
Example 10
A refined laurolactam was prepared by the same procedures as in
Example 4, except that the starting cyclododecanone material was
prepared by pre-treating a unrefined cyclododecanone material
containing 3,200 ppm of cyclododecenol with toluenesulfonic acid at
220.degree. C. for one hour, and subjecting the resultant
pretreatment reaction mixture to precision distillation. In the
pretreated cyclododecanone material, the content of cyclododecenol
was 80 ppm.
The resultant refined laurolactam exhibited an LT.diff of 5.4%.
Laurolactam having high quality can be produced with high
efficiency and stability by the process of the present invention in
which the content of each of oxygen atom-containing organic
compounds having 12 carbon atoms and cycloaliphatic unsaturated
hydrocarbon compounds having 12 carbon atoms, contained in the
starting cyclododecanone material is controlled to 1,000 ppm or
less.
* * * * *